/**
 * angular-ui-sortable - This directive allows you to jQueryUI Sortable.
 * @version v0.13.4 - 2015-06-07
 * @link http://angular-ui.github.com
 * @license MIT
 */

(function(window, angular, undefined) {
    'use strict';
    /*
     jQuery UI Sortable plugin wrapper

     @param [ui-sortable] {object} Options to pass to $.fn.sortable() merged onto ui.config
     */
    angular.module('ui.sortable', [])
        .value('uiSortableConfig',{})
        .directive('uiSortable', [
            'uiSortableConfig', '$timeout', '$log',
            function(uiSortableConfig, $timeout, $log) {
                return {
                    require: '?ngModel',
                    scope: {
                        ngModel: '=',
                        uiSortable: '='
                    },
                    link: function(scope, element, attrs, ngModel) {
                        var savedNodes;

                        function combineCallbacks(first,second){
                            if(second && (typeof second === 'function')) {
                                return function() {
                                    first.apply(this, arguments);
                                    second.apply(this, arguments);
                                };
                            }
                            return first;
                        }

                        function getSortableWidgetInstance(element) {
                            // this is a fix to support jquery-ui prior to v1.11.x
                            // otherwise we should be using `element.sortable('instance')`
                            var data = element.data('ui-sortable');
                            if (data && typeof data === 'object' && data.widgetFullName === 'ui-sortable') {
                                return data;
                            }
                            return null;
                        }

                        function hasSortingHelper (element, ui) {
                            var helperOption = element.sortable('option','helper');
                            return helperOption === 'clone' || (typeof helperOption === 'function' && ui.item.sortable.isCustomHelperUsed());
                        }

                        // thanks jquery-ui
                        function isFloating (item) {
                            return (/left|right/).test(item.css('float')) || (/inline|table-cell/).test(item.css('display'));
                        }

                        function getElementScope(elementScopes, element) {
                            var result = null;
                            for (var i = 0; i < elementScopes.length; i++) {
                                var x = elementScopes[i];
                                if (x.element[0] === element[0]) {
                                    result = x.scope;
                                    break;
                                }
                            }
                            return result;
                        }

                        function afterStop(e, ui) {
                            ui.item.sortable._destroy();
                        }

                        var opts = {};

                        // directive specific options
                        var directiveOpts = {
                            'ui-floating': undefined
                        };

                        var callbacks = {
                            receive: null,
                            remove:null,
                            start:null,
                            stop:null,
                            update:null
                        };

                        var wrappers = {
                            helper: null
                        };

                        angular.extend(opts, directiveOpts, uiSortableConfig, scope.uiSortable);

                        if (!angular.element.fn || !angular.element.fn.jquery) {
                            $log.error('ui.sortable: jQuery should be included before AngularJS!');
                            return;
                        }

                        if (ngModel) {

                            // When we add or remove elements, we need the sortable to 'refresh'
                            // so it can find the new/removed elements.
                            scope.$watch('ngModel.length', function() {
                                // Timeout to let ng-repeat modify the DOM
                                $timeout(function() {
                                    // ensure that the jquery-ui-sortable widget instance
                                    // is still bound to the directive's element
                                    if (!!getSortableWidgetInstance(element)) {
                                        element.sortable('refresh');
                                    }
                                }, 0, false);
                            });

                            callbacks.start = function(e, ui) {
                                if (opts['ui-floating'] === 'auto') {
                                    // since the drag has started, the element will be
                                    // absolutely positioned, so we check its siblings
                                    var siblings = ui.item.siblings();
                                    var sortableWidgetInstance = getSortableWidgetInstance(angular.element(e.target));
                                    sortableWidgetInstance.floating = isFloating(siblings);
                                }

                                // Save the starting position of dragged item
                                ui.item.sortable = {
                                    model: ngModel.$modelValue[ui.item.index()],
                                    index: ui.item.index(),
                                    source: ui.item.parent(),
                                    sourceModel: ngModel.$modelValue,
                                    cancel: function () {
                                        ui.item.sortable._isCanceled = true;
                                    },
                                    isCanceled: function () {
                                        return ui.item.sortable._isCanceled;
                                    },
                                    isCustomHelperUsed: function () {
                                        return !!ui.item.sortable._isCustomHelperUsed;
                                    },
                                    _isCanceled: false,
                                    _isCustomHelperUsed: ui.item.sortable._isCustomHelperUsed,
                                    _destroy: function () {
                                        angular.forEach(ui.item.sortable, function(value, key) {
                                            ui.item.sortable[key] = undefined;
                                        });
                                    }
                                };
                            };

                            callbacks.activate = function(e, ui) {
                                // We need to make a copy of the current element's contents so
                                // we can restore it after sortable has messed it up.
                                // This is inside activate (instead of start) in order to save
                                // both lists when dragging between connected lists.
                                savedNodes = element.contents();

                                // If this list has a placeholder (the connected lists won't),
                                // don't inlcude it in saved nodes.
                                var placeholder = element.sortable('option','placeholder');

                                // placeholder.element will be a function if the placeholder, has
                                // been created (placeholder will be an object).  If it hasn't
                                // been created, either placeholder will be false if no
                                // placeholder class was given or placeholder.element will be
                                // undefined if a class was given (placeholder will be a string)
                                if (placeholder && placeholder.element && typeof placeholder.element === 'function') {
                                    var phElement = placeholder.element();
                                    // workaround for jquery ui 1.9.x,
                                    // not returning jquery collection
                                    phElement = angular.element(phElement);

                                    // exact match with the placeholder's class attribute to handle
                                    // the case that multiple connected sortables exist and
                                    // the placehoilder option equals the class of sortable items
                                    var excludes = element.find('[class="' + phElement.attr('class') + '"]:not([ng-repeat], [data-ng-repeat])');

                                    savedNodes = savedNodes.not(excludes);
                                }

                                // save the directive's scope so that it is accessible from ui.item.sortable
                                var connectedSortables = ui.item.sortable._connectedSortables || [];

                                connectedSortables.push({
                                    element: element,
                                    scope: scope
                                });

                                ui.item.sortable._connectedSortables = connectedSortables;
                            };

                            callbacks.update = function(e, ui) {
                                // Save current drop position but only if this is not a second
                                // update that happens when moving between lists because then
                                // the value will be overwritten with the old value
                                if(!ui.item.sortable.received) {
                                    ui.item.sortable.dropindex = ui.item.index();
                                    var droptarget = ui.item.parent();
                                    ui.item.sortable.droptarget = droptarget;

                                    var droptargetScope = getElementScope(ui.item.sortable._connectedSortables, droptarget);
                                    ui.item.sortable.droptargetModel = droptargetScope.ngModel;

                                    // Cancel the sort (let ng-repeat do the sort for us)
                                    // Don't cancel if this is the received list because it has
                                    // already been canceled in the other list, and trying to cancel
                                    // here will mess up the DOM.
                                    element.sortable('cancel');
                                }

                                // Put the nodes back exactly the way they started (this is very
                                // important because ng-repeat uses comment elements to delineate
                                // the start and stop of repeat sections and sortable doesn't
                                // respect their order (even if we cancel, the order of the
                                // comments are still messed up).
                                if (hasSortingHelper(element, ui) && !ui.item.sortable.received &&
                                    element.sortable( 'option', 'appendTo' ) === 'parent') {
                                    // restore all the savedNodes except .ui-sortable-helper element
                                    // (which is placed last). That way it will be garbage collected.
                                    savedNodes = savedNodes.not(savedNodes.last());
                                }
                                savedNodes.appendTo(element);

                                // If this is the target connected list then
                                // it's safe to clear the restored nodes since:
                                // update is currently running and
                                // stop is not called for the target list.
                                if(ui.item.sortable.received) {
                                    savedNodes = null;
                                }

                                // If received is true (an item was dropped in from another list)
                                // then we add the new item to this list otherwise wait until the
                                // stop event where we will know if it was a sort or item was
                                // moved here from another list
                                if(ui.item.sortable.received && !ui.item.sortable.isCanceled()) {
                                    scope.$apply(function () {
                                        ngModel.$modelValue.splice(ui.item.sortable.dropindex, 0,
                                            ui.item.sortable.moved);
                                    });
                                }
                            };

                            callbacks.stop = function(e, ui) {
                                // If the received flag hasn't be set on the item, this is a
                                // normal sort, if dropindex is set, the item was moved, so move
                                // the items in the list.
                                if(!ui.item.sortable.received &&
                                    ('dropindex' in ui.item.sortable) &&
                                    !ui.item.sortable.isCanceled()) {

                                    scope.$apply(function () {
                                        ngModel.$modelValue.splice(
                                            ui.item.sortable.dropindex, 0,
                                            ngModel.$modelValue.splice(ui.item.sortable.index, 1)[0]);
                                    });
                                } else {
                                    // if the item was not moved, then restore the elements
                                    // so that the ngRepeat's comment are correct.
                                    if ((!('dropindex' in ui.item.sortable) || ui.item.sortable.isCanceled()) &&
                                        !hasSortingHelper(element, ui)) {
                                        savedNodes.appendTo(element);
                                    }
                                }

                                // It's now safe to clear the savedNodes
                                // since stop is the last callback.
                                savedNodes = null;
                            };

                            callbacks.receive = function(e, ui) {
                                // An item was dropped here from another list, set a flag on the
                                // item.
                                ui.item.sortable.received = true;
                            };

                            callbacks.remove = function(e, ui) {
                                // Workaround for a problem observed in nested connected lists.
                                // There should be an 'update' event before 'remove' when moving
                                // elements. If the event did not fire, cancel sorting.
                                if (!('dropindex' in ui.item.sortable)) {
                                    element.sortable('cancel');
                                    ui.item.sortable.cancel();
                                }

                                // Remove the item from this list's model and copy data into item,
                                // so the next list can retrive it
                                if (!ui.item.sortable.isCanceled()) {
                                    scope.$apply(function () {
                                        ui.item.sortable.moved = ngModel.$modelValue.splice(
                                            ui.item.sortable.index, 1)[0];
                                    });
                                }
                            };

                            wrappers.helper = function (inner) {
                                if (inner && typeof inner === 'function') {
                                    return function (e, item) {
                                        var innerResult = inner.apply(this, arguments);
                                        item.sortable._isCustomHelperUsed = item !== innerResult;
                                        return innerResult;
                                    };
                                }
                                return inner;
                            };

                            scope.$watch('uiSortable', function(newVal /*, oldVal*/) {
                                // ensure that the jquery-ui-sortable widget instance
                                // is still bound to the directive's element
                                var sortableWidgetInstance = getSortableWidgetInstance(element);
                                if (!!sortableWidgetInstance) {
                                    angular.forEach(newVal, function(value, key) {
                                        // if it's a custom option of the directive,
                                        // handle it approprietly
                                        if (key in directiveOpts) {
                                            if (key === 'ui-floating' && (value === false || value === true)) {
                                                sortableWidgetInstance.floating = value;
                                            }

                                            opts[key] = value;
                                            return;
                                        }

                                        if (callbacks[key]) {
                                            if( key === 'stop' ){
                                                // call apply after stop
                                                value = combineCallbacks(
                                                    value, function() { scope.$apply(); });

                                                value = combineCallbacks(value, afterStop);
                                            }
                                            // wrap the callback
                                            value = combineCallbacks(callbacks[key], value);
                                        } else if (wrappers[key]) {
                                            value = wrappers[key](value);
                                        }

                                        opts[key] = value;
                                        element.sortable('option', key, value);
                                    });
                                }
                            }, true);

                            angular.forEach(callbacks, function(value, key) {
                                opts[key] = combineCallbacks(value, opts[key]);
                                if( key === 'stop' ){
                                    opts[key] = combineCallbacks(opts[key], afterStop);
                                }
                            });

                        } else {
                            $log.info('ui.sortable: ngModel not provided!', element);
                        }

                        // Create sortable
                        element.sortable(opts);
                    }
                };
            }
        ]);

})(window, window.angular);
